Wristwatch having an hourglass face



FIG. 1 is a top and right front perspective view of a wristwatch showing my new design, the broken line showing of a band is environmental only and forms no part of the claimed design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a right side elevational view thereof; and,

FIG. 7 is a left side elevational view thereof. 

The ornamental design for a wristwatch having an hourglass face, as shown and described. 